Typical smart locks sold in the market are NFC lock, fingerprint lock and keypad lock. The problem with NFC lock is that the card going with is easy to be damaged, and the trouble that both of the fingerprint lock and keypad lock have is that the password is easy to be cracked with silver powder.
An alternative of the prior art is to switch to sound recognition, in which password is replaced with a unique audio file, such as playing a melody as a sound password to perform the unlock operation. However, the sound password entry is not safe because the data that describes a sound is vulnerable to being pilfered. If the unlock algorithm is comparatively simple, the sound data associated with a lock might be copied through eavesdrop and recording, even copied through surveillance tapes.
In order to solve the problems of the prior art, such that the password lock is easy to be cracked and low in safety, the present invention provides a sound password unlocking method and a sound password smart lock based on adaptive noise cancellation for improving the safety.